In North Carolina, research at North Carolina State University have developed a simple, effective and relatively inexpensive technique for removing lignin from the plant material used to make biofuels, which may drive down the cost of biofuel production. The work was recently published in the journal Green Chemistry.

Specifically, the researchers use protic ionic liquids to dissolve lignin from biomass, leaving behind the energy-rich cellulose which can be used to make biofuels. The lignin can then be removed from the liquid, allowing the liquid to be used repeatedly. (The protic ionic liquids in this case are essentially just vinegar and a base.)

The remaining PIL-lignin liquid mixture can then be heated to distill (or vaporize) the PIL, leaving the lignin behind as a black powder. The vapors from the PIL are collected and cooled to recover the liquid PIL so that it can be re-used. The lignin is also valuable, because it can be used to manufacture polymers or other chemical products which could supplement the cost of running the biofuel production facility.